Re: [PATCH v2 05/12] KVM: x86: fast emulate repeat string write instructions

[Xiao Guangrong]

On 08/03/2011 04:10 PM, Avi Kivity wrote:
> On 08/02/2011 02:09 PM, Xiao Guangrong wrote:
>> We usually use repeat string instructions to clear the page, for example,
>> we call memset to clear a page table, stosb is used in this function, and
>> repeated for 1024 times, that means we should occupy mmu lock for 1024 times
>> and walking shadow page cache for 1024 times, it is terrible
>>
>> In fact, if it is the repeat string instructions emulated and it is not a
>> IO/MMIO access, we can zap all the corresponding shadow pages and return to the
>> guest, then the mapping can became writable and we can directly write the page
>>
> 
> This isn't needed if we zap before emulating, right?
> 

Yes, it is, i will improve it.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/